The pointercancel event is fired when the browser determines that there are unlikely to be any more pointer events, or if after the pointerdown event is fired, the pointer is then used to manipulate the viewport by panning, zooming, or scrolling.
Some examples of situations that will trigger a pointercancel event:
A hardware event occurs that cancels the pointer activities. This may include, for example, the user switching applications using an application switcher interface or the "home" button on a mobile device.
The device's screen orientation is changed while the pointer is active.
The browser decides that the user started pointer input accidentally. This can happen if, for example, the hardware supports palm rejection to prevent a hand resting on the display while using a stylus from accidentally triggering events.
The touch-action CSS property prevents the input from continuing.